Abstract: A laser device is equipped with an exciting optical system having a GaN semiconductor laser and a condensing lens; and a resonator having of a dichroic mirror and an output mirror, and a solid laser medium is disposed within the resonator. The solid laser medium is disposed in the resonator such that the c axis of a crystal is parallel to the x axis. The exciting optical system is disposed such that the direction in which excitation light emitted from the GaN semiconductor laser is polarized is parallel to the y axis, and is formed so as to absorb excitation light in the crystal axis perpendicular to the c axis. The direction in which the oscillation light emitted from the solid laser medium is polarized coincides with a direction parallel to the c-axis direction, and also coincides with a direction along the x axis.

Abstract: A method and apparatus for accurately retrieving the position of an optical feature. The method uses the optical properties of biaxial crystals to conically refract the optical feature and transform the image of the optical feature to a circular ring structure. The position of the optical feature is then calculated by locating a center point associated with the circular ring structure.

Abstract: A YAG/Nd:YAG block where an Nd:YAG block ends in a peak integrated inside a YAG block. The YAG block has reflective surfaces positioned at 45° to one another. The angled reflective surfaces serve as a “mirror” within the laser cavity to effectively increase the length of the cavity by a factor greater than 2. Fused to the output end of the laser cavity are a polarizer, an active/passive Q-switch, a one quarter waveplate and an output coupler. In operation, the laser cavity is pumped either from the side or the end of the cavity. The optical components of the present invention are bonded to form one optical ‘block’. All the components are prealigned during the crystal manufacturing process to form the optical laser cavity. The width of the cavity should be selected such that nearly all of the laser diode pump output is absorbed by the cavity.

Abstract: A device contains at least one wavelength-tunable element controlled by an applied voltage and at least two resonant cavities, where the resonant wavelength of the tunable element is preferably elecrooptically tuned using the quantum confined Stark effect around the resonant wavelength of the other cavity or cavities, resulting in a modulated transmittance of the system. A light-emitting medium is preferably introduced into one of the cavities, permitting the optoelectronic device to work as an intensity-modulated light-emitting diode or diode laser by applying an injection current. The device preferably contains at least three electric contacts to apply a forward or a reverse bias and may operate as a vertical cavity surface emitting light-emitter or modulator or as a tilted cavity light emitter or modulator. Adding a few modulator sections enables applications in semiconductor optical amplifiers, frequency converters or lock-in optical amplifiers.

Abstract: A mode-locked laser employs a coupled-polarization scheme for efficient longitudinal pumping by reshaped laser diode bars. One or more dielectric polarizers are configured to reflect a pumping wavelength having a first polarization and to reflect a lasing wavelength having a second polarization. A Yb-doped gain medium can be used that absorbs light having a first polarization and emits light having a second polarization. Using such pumping with laser cavity dispersion control, pulse durations of less than 100 fs can be achieved.

Abstract: Conventionally, a laser beam is amplified by making a single pass through an amplifier but the laser beam emitted from the oscillator generally has low energy, so the energy stored in the amplifier cannot be fully extracted and only low laser output power and overall efficiency result. According to the method of the invention for amplifying a solid-state laser, the laser beam is passed through the amplifier multiple times and with spatial uniformity so as to achieve efficient extraction of the energy stored in the amplifier and the thermally induced distortion of the laser beam can be compensated by the single amplifier.

Abstract: A wavelength selection filter, a wavelenth selection laser, and a tunable laser for suppressing adverse effects of non-selected light when selected light is obtained by the wavelength selection filter. A linear polarizer is arranged on a side of the wavelength selection filter from which incoming light enters, and a first faraday element and a second faraday element arranged at respective locations between the linear polarizer and the wavelength selection filter, and between the wavelength selection filter and a reflection mirror for reflecting light having passed through the wavelength selection filter. After incoming light passes through a linear polarizer, selected light passes through the wavelength selection filter and is reflected by the reflection mirror, while non-selected light is reflected by the wavelength selection filter. The selected light and the non-selected light differ in the number of times they pass through faraday elements before they return to the linear polarizer.

Abstract: A method of operating a stretched-pulse Raman fiber laser includes producing laser radiation gain in a laser cavity using predominantly Raman amplification. Such a stretched-pulse Raman fiber laser has a laser cavity that includes a Negative Group Velocity Dispersion Fiber connected in series with a Positive Group Velocity Dispersion Fiber, a polarization controller and an isolator. In some examples, the Negative Group Velocity Dispersion Fiber is a Dispersion Compensating Fiber. In other examples, the Negative Group Velocity Dispersion Fiber is replaced by a Raman Specialty Fiber.

Abstract: To provide a surface-emitting light emitting device including an optical member whose mounting position, form, and size have been favorably controlled, and a method of manufacturing the same, as well as an optical module and an optical transmission apparatus that include this surface-emitting light emitting device, the surface-emitting light emitting device of the present invention can emit light perpendicular to a substrate and includes an emitting surface that emits the light, a base member that is provided on the emitting surface, and an optical member that is provided on an upper surface of the base member.

Abstract: A magneto-optic variable optical attenuator is provided that is used to control the intensity of a light signal. The optical attenuator includes at least one polarizing element having an optical polarization axis, wherein the polarizing element transmits a portion of an incident light signal proportional to the angular difference between an optical polarization axis of the incident light signal and that of the polarizing element. The optical attenuator also comprises a variable faraday rotator that includes a semi-transparent material, a magnetic material for applying a magnetic force to a light signal that is passed through the semi-transparent material, and a conductive wire configured to induce a magnetic field on the magnetic material. In various embodiments, the optical attenuator is employed as part of a laser package that includes a laser light source and a plurality of polarizing elements, which are in optical communication with a faraday rotator and/or a variable faraday rotator.

Abstract: A solid state zig-zag slab laser amplifier in which depolarization occurring at total internal reflection from opposed lateral faces of the amplifier slab is controlled by selecting a complex evanescent coating that provides a selected phase retardance that results in minimization of depolarization. Without use of the complex coating, small changes in incidence angles can result in phase retardance changes large enough to increase depolarization significantly, especially when the amplifier is operated at higher powers. Appropriate selection of the complex evanescent coating allows a desired phase retardance angle to be maintained relatively constant over a small range of angles of incidence, at a given wavelength, and therefore permits minimization of depolarization and birefringence effects.

Abstract: A semiconductor laser device has a semiconductor laser and a polarizing diffraction grating that is arranged ahead of the semiconductor laser. A reflected light from an optical recording medium is diffracted by the polarizing diffraction grating according to the polarization direction of the reflected light. The reflected light is thereby deviated from the direction toward the semiconductor laser to prevent the reflected light from returning to the semiconductor laser.

Abstract: A laser is disclosed which includes a gain medium, a switch element, and a pulse controller. In one embodiment laser light of differing polarizations pass along respective paths and a pulsed laser output is generated via an electro-optical element. In another embodiment light of differing polarizations passes in differing directions through a cyclical path. The invention can make use of a prism-shaped polarizer having a polarization selection face and two further faces. Yet further initial pulses can be controlled to reduce energy, for example by progressively increasing the period or amplitude of successive pulses. As a result an efficient and high power laser apparatus is realized.

Abstract: A laser is disclosed which includes a gain medium, a switch element, and a pulse controller. In one embodiment laser light of differing polarizations pass along respective paths and a pulsed laser output is generated via an electro-optical element. In another embodiment light of differing polarizations passes in differing directions through a cyclical path. The invention can make use of a prism-shaped polarizer having a polarization selection face and two further faces. Yet further initial pulses can be controlled to reduce energy, for example by progressively increasing the period or amplitude of successive pulses. As a result an efficient and high power laser apparatus is realized.

Abstract: An optical system for reforming a laser beam with azimuthal polarization having X and Y components into a beam with linear polarization has a multiplicity of optical elements, at least one of which has a mirror having an absorbing thin film reflective coating to remove the Y-component of the azimuthal beam polarization, thereby reflecting only the X or linear component as a linearly polarized beam. The absorbing thin film reflective coating is comprised of a plurality of layers alternately having high and low indices of refraction. The optical elements include a spatial filter and the beam is passed through the spatial filter to adjust the beam quality. At least one other optical element is collimating and the beam with adjusted beam quality is transmitted to the collimating element to effect its collimation. The collimated linearly polarized laser beam may thereafter be passed through a phase shifter to convert the polarization of the laser beam from linear to circular.

Abstract: The ultrashort fiber laser with a dispersion-managed cavity. The laser is an actively mode-locked sigma laser, typically locked at a repetition rate of 10 GHz, driven by an external frequency source and actively length stabilized, and nearly 10,000 pulses circulate within the laser cavity. A Mach-Zehnder modulator is placed in a loop of polarization-maintaining (PM) fiber. The polarization state of light injected into the non-PM branch evolves in a random manner but is transformed into an orthogonal state by a Faraday mirror; linearly polarized light injected into the branch by a polarizing beamsplitter returns to the beamsplitter also linearly polarized but rotated by 90°. The cavity of the laser is composed of several fibers. The average dispersion Dav is anomalous and is approximately equal to 0.1 ps/(nm·km).

Abstract: A CPT detector and a method for detecting CPT are disclosed. The CPT detector includes a quantum absorber, a polarization analyzer, and a detector. The quantum absorber includes a material having first and second low energy states coupled to a common high energy state. Transitions between the first low energy state and the common high energy state and between the second low energy state and the common high energy state are induced by electromagnetic radiation having a predetermined polarization state. The polarization analyzer blocks electromagnetic radiation of the predetermined polarization while passing electromagnetic radiation having a polarization state that is orthogonal to the predetermined polarization. The polarization analyzer is irradiated with a portion of the generated electromagnetic radiation that has passed through the quantum absorber. The detector generates a signal related to the intensity of electromagnetic radiation that leaves the polarization analyzer.

Abstract: Apparatus for reducing spacing between a plurality of parallel, spaced apart plane-polarized laser-radiation beams delivered by a stack of laser-diode bars includes a ninety degree polarization rotator, and a compound prism including a total reflecting surface an internal polarization-selective surface parallel to each other. The polarization-selective surface is highly transmissive for radiation plane-polarized in one polarization orientation and highly reflective for radiation plane-polarized at ninety degrees to that orientation. The polarization rotator rotates the polarization of a portion of the beams. The beams are transmitted through the compound prism with the portion of polarization-rotated beams following a different path through the prism from that of the beams that are not polarization rotated. The beams exit the prism with spacing therebetween one-half of the spacing between beams entering the prism.

Abstract: A laser polarization control apparatus includes a polarization modifying device, such as a liquid crystal variable retarder, and a controller. The polarization modifying device receives a laser beam and modifies the polarization of the laser beam. The controller, which is connected to the polarization modifying device, adjusts an input to the polarization modifying device in order to control modification of the polarization of the laser beam based on alignment of a structure to be processed by the laser beam. For example, the polarization of the laser beam may be rotated to correspond with the alignment of a link in a semiconductor device to be cut by the laser beam. The polarization modifying device is configured for incorporation into a laser processing system that produces the laser beam received by the polarization modifying device and that focuses the laser beam modified by the polarization modifying device onto a workpiece that includes the structure to be processed by the laser beam.

Abstract: A system and method for VCSEL (vertical cavity surface emitting laser) polarization control is disclosed, including methods and apparatus comprising a component package (302, 304) having self-aligning features (316, 318), for indicating an alignment axis (320, 322), and an upper surface aperture (314) formed therein, a vertical cavity surface emitting laser device (308) having two emission polarizations (204) normal to one another, disposed within the component package and aligned such that each emission polarization is at about 45 degrees with respect to the alignment axis, and a linear polarization element (400, 402, 406) having a polarization direction (206), spanning the aperture and disposed such that the polarization direction is parallel to the alignment axis.

Abstract: A dual wavelength optical fiber distributed feedback laser comprises a pump laser coupled to a birefringent fiber in which a first grating device (two co-located single phase-shift fiber Bragg gratings (FBGs)) is provided. The grating device gives the laser two potential lasing modes in each of two orthogonal polarization states. A polarization mode coupling FBG selects two orthogonally polarized modes on which the laser oscillates. In a photonic data carrying signal source, the laser is coupled to a polarization dependent, optical modulator operable to apply a modulation, at a data signal frequency, to one polarization mode of the laser output. In an optical waveguide based electronic signal transmission system the modulated and un-modulated polarization modes output from the source are transmitted across a fiber transmission line to a polarizing optical fiber in which the two modes heterodyne to generate an electronic carrier signal in the optical domain.

Abstract: An optical resonator supporting two sets of simultaneously co-existent oscillation modes (30 and 31), having polarizations orthogonal to each other. Mode control elements (28 and 29), such as apertures and phase elements, are introduced into the resonator to allow only preferred modes to exist. The placement and orientation of the sets are designed such that the high intensity zones of one set fall on the nodes or low intensity zones of the other set in an interlaced pattern. Thus, in a laser resonator, better utilization of the gain medium (24) is achieved and the beam quality and brightness over multimode lasing are improved. This configuration improves the performance of high Fresnel number resonators, in both pulsed and continuous lasers, for applications such as scribing, drilling, cutting, target designation and rangefinding. An application of the intra-cavity coherent summation of orthogonally polarized modes is described, whereby azimuthally or radially polarized beams may be obtained.

Abstract: Apparatus for reducing spacing between a plurality of parallel, spaced apart plane-polarized laser-radiation beams delivered by a stack of laser-diode bars includes a ninety degree polarization rotator, and a compound prism including a total reflecting surface an internal polarization-selective surface parallel to each other. The polarization-selective surface is highly transmissive for radiation plane-polarized in one polarization orientation and highly reflective for radiation plane-polarized at ninety degrees to that orientation. The polarization rotator rotates the polarization of a portion of the beams. The beams are transmitted through the compound prism with the portion of polarization-rotated beams following a different path through the prism from that of the beams that are not polarization rotated. The beams exit the prism with spacing therebetween one-half of the spacing between beams entering the prism.

Abstract: A fundamental laser beam to is wavelength converted through nonlinear optical crystals by traveling in one direction, sequentially through two nonlinear optical crystals arranged in series. A wavelength-converted laser beam is generated and includes wavelength-converted laser beams having polarized directions differing from each other by angles in a range from 45° to 90°. The two nonlinear optical crystals have crystal orientation axes differing by 45° to 90° when viewed along the optical axis of the laser beam.

Abstract: A laser oscillator comprises a laser medium, an optical excitation laser diode that irradiates the laser medium with light, a polarizer disposed on an optical path of the laser medium at a first end thereof, a first Porro prism disposed with the optical path coinciding with a point on a ridgeline thereof and with the ridgeline parallel or perpendicular to a plane of incidence of the polarizer, and a second Porro prism disposed on the optical path of the laser medium at a second end thereof with the optical path coinciding with a point on a ridgeline thereof. An angle formed by the two ridgelines of the first and second Porro prisms is a predetermined angle other than 0 degrees, 90 degrees, 60 degrees, 45 degrees and 36 degrees, 30 degrees.

Abstract: The present invention relates to vertical-cavity surface-emitting lasers (VCSELs), and more particularly to a method and apparatus for controlling and stabilization of polarization in such devices. The method for stabilizing the polarization of light generated by a VCSEL assembly comprising a light generation region of a VCSEL, the VCSEL being mechanically coupled to a mounting substrate, comprises the steps of: mechanically coupling the mounting substrate to a second substrate which is coextensive or larger in area than the mounting substrate, and applying uniaxial strain to the light generation region of the VCSEL by means of external strain applied to the mounting substrate by the second substrate or by means attached to the second substrate.

Abstract: A method for generating polarized laser output radiation utilizes a laser resonator whose active medium exhibits thermally induced birefringence. The radiation fields oscillating in the laser resonator are not subjected to polarization selection, and only the radiation field exhibiting the desired polarization state (p) is partially output. Only a prescribed polarization of the radiation fields of the laser radiation which can oscillate in the resonator can be partially output from the resonator with a prescribed output level and all differently polarized radiation fields remain in the resonator in a completely reflecting fashion.

Abstract: A one piece laser assembly including a rod of gain medium with one end-face bonded to a broad end-face on a stack of optical wafers that process light differently and mirrors plated on the remaining exposed end-faces of the rod and the stack of wafers.

Abstract: A laser is disclosed which includes a gain medium, a switch element, and a pulse controller. In one embodiment laser light of differing polarizations pass along respective paths and a pulsed laser output is generated via an electro-optical element. In another embodiment light of differing polarizations passes in differing directions through a cyclical path. The invention can make use of a prism-shaped polarizer having a polarization selection face and two further faces. Yet further initial pulses can be controlled to reduce energy, for example by progressively increasing the period or amplitude of successive pulses. As a result an efficient and high power laser apparatus is realized.

Abstract: Described are optical devices called retro-reflective etalon filter and wide tunable semiconductor lasers using the retro-reflective etalon filter. The reflection optical spectrum of the retro-reflective etalon has the double-pass transmission characteristic of the etalon used within the retro-reflective etalon. The retro-reflective etalon(s) can be used as the reflective end mirror(s) of the wide tunable semiconductor laser. The retro-reflective etalon also can act as the wavelength locker of the laser. The proposed retro-reflective etalon is easy to be manufactured and the wide tunable semiconductor lasers are easy to be implemented by using the retro-reflective etalon.

Abstract: An optical arrangement for direction dependent coupling out of light comprises a first and a second polarization converter each for converting the state of polarization of light received in a predetermined way. A polarization dependent coupling device is adapted for coupling out a portion of the light received, whereby the ratio of the coupled out portion substantially depends on the state of polarization of the light received. The polarization dependent coupling device is arranged between the first and the second polarization converters, and the optical arrangement receives from different sides light beams propagating in different directions. The characteristics of the first and the second polarization converters are adapted such that the polarization dependent coupling device receives light beams propagating with different states of polarization in the different directions.

Abstract: The present invention is directed to a device for reflecting a select polarization of at least one transmission having a given wavelength impinging upon the device. The device includes a substrate and a layer of nanostructures. The nanostructures form a resonant pattern on the substrate adapted to define a plurality of high contrast refractive index interfaces suitable for reflecting the select polarization of the at least one transmission.

Abstract: The inventive rod includes a gain medium having first and second equal length portions sharing a common optical axis and an optical rotator disposed between said first and second portions which optical rotator compensates for birefringence. In an exemplary case, the optical rotator includes first and second waveplates optically coupled to one another and oriented with respect to one another by a predetermined angle, where the first waveplate receives a polarized beam having a first state, and the second waveplate produces the polarized beam having a second state, the first and second states differing from one another by 90°. Multiple rotators can be employed to compensate strongly birefringent rods, each rotator compensating a section of a rod constructed from a plurality of equal length optical gain elements.

Abstract: The invention concerns a light reflecting element comprising a substrate (10), a multilayer mirror (20) and optical coupling means (32, 40) comprising a diffraction grating (40); whereby the reflection coefficient of one polarization is damped without damping the reflection coefficient of the orthogonal polarization over a broad wavelength range and with a large tolerance on the optogeometrical parameters of the device.

Abstract: There are provided a wavelength selection device, a wavelength selection laser, and a tunable laser for suppressing adverse effects of non-selected light when selected light is obtained by the wavelength selection device. A linear polarizer is arranged on a side of the wavelength selection filter from which an incoming light enters, and a first faraday element and a second faraday element each for rotating the polarization of light by 45 degrees are arranged at respective locations between the linear polarizer and the wavelength selection filter, and between the wavelength selection filter and a reflection mirror for reflecting light having passed through the wavelength selection filter. After then incoming light has passed through the linear polarizer, selected light passes through the wavelength selection filter and is reflected by the reflection mirror, while non-selected light is reflected by the wavelength selection filter.

Abstract: Apparatus and method for controlling the length of a laser cavity comprises a laser diode that is configured to produce a beam of energy, the laser diode has a first end and an output end, the first end being in optical communication with a highly reflective mirror. A wave guide having a receiving end and a transmission end is also provided, with the wave guide being comprised of an electro-optical material, wherein the receiving end is in optical communication with the output end, and the transmission end is in optical communication with an output coupler. A plurality of electrodes are disposed along a longitudinal axis of the wave guide, wherein the voltage on each electrode is independently controlled to alter the index of refraction of the wave guide at a position adjacent each electrode. A polarizer is also provided with respect to the transmission end, with the polarizer configured to attenuate the beam of energy.

Abstract: A method of filtering an input optical signal, the method including the step of: (a) utilising the phase response of a Gires-Tournois resonator to produce a corresponding spatial separation in a predetermined wavelength range of the input optical signal. The method further preferably can include the step of: (b) projecting substantially orthogonal beams onto the surface of a Gires-Tournois resonator at slightly different angles of incidence and utilising the phase difference in the phase response of the orthogonal beams to spatially separate the predetermined wavelength range. A birefringent wedge can be utilised to separate a polarised input beam into the substantially orthogonal beams for projection onto the surface of the Gires-Tournois resonator.

Abstract: Active element for a laser source and laser source comprising such an active element. According to the invention, the active element for a laser source comprises an elongate rod comprising a doped matrix capable of absorbing a pump beam in order to amplify laser radiation propagating longitudinally, at least one input face for the pump beam, a first reflection face for the pump beam which is inclined with respect to the longitudinal axis of the rod and at least one interacting second reflection face, at least one of the input face and second reflection face being equally inclined.

Abstract: In order to facilitate control of the polarization plane of a laser beam emerging from a surface-emitting-type semiconductor laser in a specific direction and to suppress occurrence of fluctuations and switching of the polarization plane depending on the optical output and the environmental temperature, a strain generating section (19) is arranged adjacent to a resonator (10B) of a semiconductor laser. The strain generating section (19) impresses anisotropic stress to the resonator (10B) to generate strain, resulting in birefringence and dependence of the gain on the polarization in the resonator (10A). This enables stabilized control of the polarization plane.

Abstract: The invention provides a UV below 200 mm lithography method. The invention includes providing a below 200 mm radiation source for producing <200-nm light, providing a plurality of mixed cubic flouride crystal optical elements, with the fluoride crystals comprised of a combination of alkaline earth cations having different optical polarizabilities such as to produce an overall isotropic polarizability which minimizes the fluoride crystal spatial dispersion below 200 nm, transmitting <200-nm light through the cubic fluoride crystal optical elements, forming a lithography pattern with the light, reducing the litographic patter and projecting the lithography pattern with the cubic fluoride crystal optical elements onto a UV radiation sensitive lithography printing medium to form a printed lithographic pattern. The invention includes making the mixed fluoride crystals and forming optical element thereform.

Abstract: A laser arrangement comprising a ring cavity at least two gain portions in said ring cavity, an input-output coupling connected to said ring cavity, a discriminator means connected in said ring cavity and adapted to discriminate between a pumping signal and an output signal and pumping means for providing said pumping signal and connected to said gain portions of said ring cavity such that, upon activation of said pumping means, said laser arrangement operates as a laser producing a laser output at said input-output coupling.

Abstract: An apparatus for generating an optical fiber laser capable of tuning a wavelength thereof.

Abstract: The present invention provides a light source for an optical network. The light source includes a semiconductor optical gain element, having an axis of symmetry; and a mechanism for reflecting wavelengths that correspond to optical transmission channels of the optical network, the reflecting means optically coupled to the semiconductor optical gain element and intersecting the axis of symmetry. The light source of the present invention is a single multi-wavelength light source. It is designed to only emit wavelengths that specifically correspond to optical transmission channels. The mechanism of the light source suppresses possible mode hopping, thus maintaining the power stability of all channels. Since multiple wavelengths are provided in a single light source, the number of lasers required to service a network can be dramatically reduced, increasing efficiency and reducing the cost of equipment and time for maintenance as well.

Abstract: A pump source for a fiber Raman amplifier uses multiple lasers to generate high pump power or to generate a pump beam having a tailored spectrum for producing a desired Raman gain spectral profile. Light from two lasers, in mutually orthogonal polarization states directed to a polarization combiner that produces an output having light mixed at the two orthogonal polarization states. A depolarizer depolarizes the output. The depolarizer defines first and second orthogonal polarization modes oriented so that the light output from the polarization combiner in one polarization state excites the first and second polarization modes of the depolarizer equally and the light output from the polarization combiner in the other polarization state also excites the first and second polarization modes of the depolarizer equally.

Abstract: The invention provides a laser system for producing a high energy amplified laser beam output from an oscillator producing a wave front of low energy laser beam, the system including at least one amplifier positioned to receive the low energy laser beam for amplification via a first polarizer; a second polarizer, positioned along the axis of the amplified beam at the output side of the amplifier, for allowing a first fraction of the beam to pass therethrough and for reflecting a second fraction of the beam from an output surface of the polarizer, the second fraction constituting the output of the system; a retroreflector, associated with a quarter wave plate, oriented to receive the first fraction and to reflect it back toward the second polarizer, and reflecting means for reflecting the reflected first fraction toward the first polarizer to be reflected toward the amplifier for further amplification and to be reflected off the output surface of the second polarizer together with the second fraction.

Abstract: A system and method for laser light amplification provides amplification of a laser light beam emitted from a laser light source as low-amplification seed laser light signal. The low-amplification seed laser light signal is transmitted to an amplification component. The amplification component amplifies the low-amplification seed laser light signal by stimulating emissions of the population inversion provided by a pumping diode to generate an amplified laser light signal. The system and method further directs the amplified laser light signal to an output destination. The result of the present invention is a system and method of operation providing higher pulse rates, improved pointing stability, and optionally variable pulse rates for a variety of uses, including for non-destructive laser ultrasonic testing of materials.

Abstract: A laser polarization control apparatus includes a polarization modifying device, such as a liquid crystal variable retarder, and a controller. The polarization modifying device receives a laser beam and modifies the polarization of the laser beam. The controller, which is connected to the polarization modifying device, adjusts an input to the polarization modifying device in order to control modification of the polarization of the laser beam based on alignment of a structure to be processed by the laser beam. For example, the polarization of the laser beam may be rotated to correspond with the alignment of a link in a semiconductor device to be cut by the laser beam. The polarization modifying device is configured for incorporation into a laser processing system that produces the laser beam received by the polarization modifying device and that focuses the laser beam modified by the polarization modifying device onto a workpiece that includes the structure to be processed by the laser beam.

Abstract: Waveguide structures comprising a thin lossy metal film of finite width embedded in an infinite homogeneous dielectric support purely bound electromagnetic modes of propagation low mode power attenuation in the neighbourhood of 10 to 0.1 dB/cm is achievable at optical communications wavelengths, with even lower values being possible. Carefully selecting the film's thickness and width can make this mode the only long-ranging one supported. In addition, the mode can have a field distribution that renders it excitable using an end-fire approach. The finite-width metal film waveguide may be used for applications requiring short propagation distances and 2-D field confinement in the transverse plane, enabling various devices to be constructed, such as couplers, splitters, modulators, interferometers, switches and periodic structures. Under certain conditions, an asymmetric structure can support a long-ranging mode having a field distribution that is suitable to excitation using an end-fire technique.

Abstract: A method for generating polarized laser output radiation utilizes a laser resonator whose active medium exhibits thermally induced birefringence. The radiation fields oscillating in the laser resonator are not subjected to polarization selection, and only the radiation field exhibiting the desired polarization state (p) is partially output. Only a prescribed polarization of the radiation fields of the laser radiation which can oscillate in the resonator can be partially output from the resonator with a prescribed output level and all differently polarized radiation fields remain in the resonator in a completely reflecting fashion.

Abstract: A double-pass birefringent filter apparatus comprises an external-interface apparatus (illustratively including of a beam-displacer element and a waveplate element); a birefringent filter comprised of a series of several birefringent waveplates; and a wrap-around unit (illustratively comprised of a beam-displacer element and a retro-reflector). In response to an input beam received at the external-interface apparatus, the double-pass birefringent filter forms two output beams having complimentary intensities which vary periodically with frequency.